1. Field of the Invention
The invention concerns an anchor construction for use in concrete walls or slabs which enables the simple and convenient attachment of parts to the wall or slab without modification of the wall or slab itself.
2. Background of the Prior Art
In order to fasten parts of an assembly, for example, pipe lines, pumps, vessels, etc., at a certain distance from a concrete wall or slab, appropriate fastening parts are needed. A special problem is posed in this respect by the anchoring of the fastening elements in concrete itself. The fastening elements may be cast in the concrete during construction of the wall or slab or may typically be inserted subsequent to construction as dowels.
Anchoring with the aid of dowels is difficult in the case of nuclear reactor construction and particularly with steel reinforced concrete structural parts, due to the danger inherent with drilling into the reinforcement. A high expenditure of labor is required to safely avoid such damage.
In conventional operations the casting of anchors in the concrete at locations where they are subsequently needed requires very early planning. In spite of all the care taken, this does not always produce satisfactory results. The concrete anchors are often needed at a location other than that initially planned. Such difficulties have been eliminated in the prior art by means of a grid-like distribution of numerous concrete anchors over a large surface.
The grid-like distribution of concrete anchors as a function of the static load on a building wall is described in West German Offenlegungsschrift No. 2911157. The concrete anchor of this reference consists of screw sockets on both sides of a wall connected by means of a rod. The distance between the anchors is kept small so that pre-planning is not critical. The closest available concrete anchor may be used. Obvious disadvantages arise under this construction as the concrete anchors must be mounted prior to the pouring of the concrete into the concrete forms. Holes are typically drilled in the forms for the anchor members, making the forms restricted for reuse.
It is further known that concrete anchors can be installed in the concrete reinforcement itself prior to the pouring of the concrete wall. This is described in British Patent Specification No. 1,080,793. The anchor has a groove formed between two flanges which is engaged by the reinforcing rods. Exact placement of the anchors is, however, difficult in this arrangement as the standardizing effect of a predetermined grid is not utilized. Without such standardization, it is necessary to adapt the fastening elements in each individual case. This in general requires the high cost of intensive welding and cutting work at the site of the installation.